Rotary drilling rig



Jan. 23, 1940.

w. T. CALDWELL ET .AL

ROTARY DRILLING RIG Filed April 6, 193a 2 Sheets-Sheet 1 I V 111 4 IVENTOR lalm i? (an 6 AEQRNEY Patented Jan. 1940 ROTARY DRILLING RIGWalter T. Caldwell and John P. Lang, Enid,

kla., assignors to The George E. Failing Supply Comp ny,

Enid, Oklahoma.

0kla., a corporation of Application April 8,1938, Serial No. 200,390

6 Claims.

This invention relates to rotary drilling rigs and particularly to thoseequipped with power augmenting apparatus for controlling or applyingpressure on a drill bit. g

Rotary drilling apparatus of this character usually employ'a hollowdrive rod that is slidably keyed to a rotary driving member and providedwith a chuck for clutchingly engaging the drill pipe that extendstherethrough. The power augmenting apparatus is connected with the drillrod so as to exert a control pressure upon the drill bit through thedrive rod, chuck, and the drill pipe engaged thereby. The effectivemovement of the power augmenting device is relatively short so that itis necessary to release the chuck and readjust it relatively to thedrill pipe many times during drilling operations, particularly whendrilling relatively soft formations where the progress of the bit israpid. This slows down the drilling time and results in high cost ofoperation.

Itis,. therefore, the principal object of the present invention toprovide a rotary drilling apparatus of this character that is equippedwith a power augmenting device whereby hydraulic pressure and rotarypower are applied directly to a conventional type kelly rod connectedinto the drilling string so that the hydraulic power may be selectivelyreleased to permit the kelly rod to be rotated and moved independentlyof thepower device.

In accomplishing this and other objects of the invention, as hereinafterpointed out, we have provided improved details of structure, thepreferred form of which is illustrated'in the accom- Fig. 4 is a'section' through the head of one of the power augmenting cylinders onthe line 3-3 of Fig. 2. a

Fig. 5 is a section through one of the cylinders on the line 5-5 of'Fig.2.

Referring more in detail to the drawings: l designates a drilling rigincluding a mast 2 that is supported upon a platform 3 carried upon thechassis of a motor vehicle I. The rear end of the platform 3 is providedwith a recess 5 within which is slidably mounted a rotary drilling unit6 constructed in accordance with the present invention.

. The unit 6 includes a base frame I, having foot flanges 8 for engagingthe platform to suspend a pair of cylinders 9 and lil'u'pon therespective sides of a driving mechanism H,later described.

The flange 1 includes a cross head i2 having a central gear housing l3and laterally extending arms N and i5 that are provided with verticalopenings lithrough which the cylinders 9 and i0 extend. The cylinders 9and it comprise tubular bodies having threaded ends I? and it formounting cap-like cylinder'heads i9 and 20 respectively. The upper heads59 engage against spacing collars 2i and '22 that are also threaded onthe upper ends of the cylinders and engage against the upper faces ofthe arms to cooperate with sleeves 23 in clamping the cylinders to thebase frame, the sleeves 23 engaging against the lower faces of the armsi5 and against the lower heads 20 of the cylinders, as clearly shown inFig. 2.

To reduce the over-all height of the unit, the cylinders are preferablymounted so that they depend through the recess in the platform but"terminate a sufiicient' distance above the ground to not interfere withmovement of the base frame out of drilling position when. it becomesnecessary to run casing or perform other operations incidental todrilling of earth formations.

slidable within the cylinders are pistons 2d and 25 to which areconnected rods 26 and 27 having their upper ends projecting throughpacking glands 28 and 29 provided in the upper cylinder heads. The outerends of the rods have reduced shanks extending through openings 3i! and3! in the arms 32 and 33 of a movable cross head 33.. The threadedshanks project through the arms and are provided with nuts 35 and 35 fordrawing the arms against the shoulders 31 .and 38 formed by the reducedextensions.

Extending laterally from the arms are integral sleeve-like bosses 39-and 40 supporting guide rods 4i and 42 slidable through openings E3 in aflange M. projecting from the base frame I, as

' best shown in Fig. 4.-

The gear housing l3 has upper and lower walls 45 and 46 provided withregistering openings s1 and 48 to mount antifriction bearings 49 and 50respectively, the outer races 5| and 52 of the bearings being retainedin fixed position withinv the openings 'by closure plates 53 and securedconnected with the sleeve.

by fastening devices, such as cap-screws and 56 respectively. The innerraces 51 and 58 of the bearings are retained against shouldered seats 59and 60 thatare provided within a driving sleeve 6| having reducedextensions 62 and 63 projecting through openings 64 and 65 of theclosure plates 53 and 54, the joints therebetween being sealed bypacking rings 66 and 61 to retain a lubricant within the gear housing.

Mounted on the upper end of the driving sleeve is a wear ring 68carrying a compressible packing 69 that is retained in compressionagainst the kelly rod I0 later described, the packing being engaged in arecess II of a retaining plate 12. The retaining plate has an annularflange I3 provided with a depending annular portion I4 engaging over anannular shoulder I5 of the upper cover plate to center the retainingplate. The retaining plateis anchored in position by fingers I6projecting inwardly from lugs 11 that are secured by the fasteningdevices 55.

Secured to the driving sleeve by means of a spline I8 is a driving gear19 having teeth engaging with a driving pinion 8| that is rotatablymounted within the gearing housing and fixed to a drive shaft 82connected with a suitable prime mover. carried upon the vehicle. Thedriving sleeve, including the retaining plate, is provided with an axialopening 83 corresponding to the cross-section of a kelly rod I0 that isextended therethrough so that when the driving sleeve is rotated thekelly rod is rotated thereby and is floatingly slidable therethroughprogressive with downward movement of the drill bit, the drill bitbeingconnected with the drill pipe attached to the lower end of the kellyrod, as in conventional practice.

Formed in the movable cross head 34. in axial alignment with the drivingsleeve, is an opening 85 for mounting the outerrraces 86 and 8'! ofantifriction bearings 88 and 89. The bearings 88 and 89 are preferablyof roller type and arranged to take thrusts acting in either directionrelatively to the longitudinal axes thereof under movement of thepistons 24 and 25. as later described, the bearings being retained inposition b annular rings 90 and 9| that are secured to the upper andlower sides of the cross head by screws 92 and 03.

The inner races 94 and 95 of the bearings carry a s eeve 96 providedwith an axial opening 91 having slidin 'fit with the kelly rod-so thatthe kellv rod projects therethrough and is drivingly The lower end ofthe sleeve has a laterally extending flange 98 supporting a spacer ring99 that engages against the inner race of the lower bearing and whichcorn r tes with a similar spacin sleeve I00 and a col ar IIII tospacingly retain the bearings relatively to the sleeve. The upper end ofthe sleeve projects above the cross head and is externally threaded. tomount the collar IOI of a chuck I02 Wherebv the cross head isselectively anchored to the kelly rod. The collar IOI rotates within theupper bearing retaining ring and is packed relatively thereto by apacking ring I03 to cooperate with a similar ring I04 mounted within thelower plate to retain a lubricant for the bearings.

The chuck I02 is best shown in Fig. 3 and has a plurality of radiallyextending bores I05 terminating in rectangular recesses to slidablymount clutch jaws I06 having transverse teeth I01 to engage the sidefaces of the kelly rod by means of adjusting screws I08 thrcadedlyengaged within bushings I09 that are threaded into the outer ends of thebores. The inner ends of the screws have heads IIO engaging withinflanged recesses of the jaws so that the screws are swivelly mountedtherein but are adapted to move the jaws to and from the kelly rod whenthe heads IIO thereon are rotated by a suitable wrench- (not shown Thechuck body also includes a cap plate I I I for retaining the jaws, thecap plate being secured to the body by cap screws II2, as shown in Figs.2 and 3.

The upper end of the kelly rod is provided with the usual swivel headII3, carrying a bail 4 connected with a tackle mechanism I I5 employedin handling the drilling string. Connected with the swivel head is theusual hose II6 through which a drilling fluid is circulated to thedrilling string through the swivel head and through an axial channel I"of the kelly rod. The pistons are moved in the cylinder to raise andlower the cross head 34 by a fluid pressure medium admitted to therespective ends of the cylinders through ports H8 and H9, the portsbeing connected by conduits I20 connected with a control Y valve I 2|,whereby pressure medium may be selectively admitted to the upper orlower portions of the cylinders, depending upon the desired direction ofmovement for the cross head 34.

In using the apparatus, the kelly rod slides freely through the sleevesso that it may be raised orlowered by means of the tackle mechanism. Thekelly rod is rotated through the driving sleeve upon rotation of thering gear 49 to effect rotation of the drill bit that is connected withthe lower end of the drilling string. When the drill bit is operatingsatisfactorily through relatively soft formations, the jaws are slackedoff from engagement with the kelly rod and the kelly rod moves freelytherethrough and through the driving sleeve progressivelyv with thedownward progress of the bit. The kelly rod is, therefore, independentof the power augmenting mechanism. Upon encountering a hard formationwhere it is desirable to apply pressure on the bit in excess of theweight of the drilling string, the

jaws are engaged with the kelly rod to grip the cross head thereto.Pressure fluid is then admitted through the upper ports of the cylindersto force the pistons downwardly and exert a downward pressure on thedrilling string.

As the depth of the hole increases, the weight of the drilling stringmay be such as to produce an excessive pressure on the drill bit. Whenthis occurs the pressure may be relieved by engaging the jaws with thekelly rod, and admitting the pressure fluid to the lower ends of thehydraulic cylinders so that a lifting force is applied on the pistons tosustain the weight of the drilling string.

It is apparent that in the structure illustrated. the rotative power isapplied directly to the kelly rod independently of the power augmentingmechanism; however, when it becomes necessary to use the power device,the jaws are engaged directly with the kelly rod so as to exert apressure control on the kelly rod as desired.

What we claim and desire to secure by Letters Patent is:

1. In a rotary drilling rig, a power augmenting unit including a pair ofcylinders, a piston in each cylinder, a rod connected with each piston,a cross head connecting the piston rods, means spacingly connecting thecylinders and forming an enclosing housing, a kelly rod driving sleevehaving a bore directly engaging a kelly rod, means rotatably mountingthe kelly rod driving sleeve in the housing, a chuck sleeve having abore passing the kelly rod, a chuck on the chuck sleeve and arranged togrip the kelly rod at ;points thereon in accordance with the length ofthe piston stroke relatively to the length of the kelly rod to efiectmovement of the kelly rod through said driving sleeve, means rotatablymounting the chuck sleeve in the cross head whereby said chuck sleeverotates with the kelly rod, and driving means in the housing havingdriving connection with the kelly rod driving sleeve. 1

2. In a rotary drilling rig, a power augmenting unit including apair ofcylinders, a piston in each cylinder, a rod connected with each piston,a cross head connecting the rods, means spacingly connecting thecylinders and forming an enclosed housing having registering openingsin'the upper and lower sides thereof, bearings supported in axialalignment with said openings, a kelly rod driving sleeve rotatablysupported in said bearings and having a bore to drivingly engage a kellyrod that is extended therethrough, reversely arranged thrust bearings inthe cross'head, a chuck sleeve rotatably supported in the thrustbearings and separate from said driving sleeve, 9. chuck carried by saidlast named sleeve having jaws arranged to grippingly engage the kellyrod, and means in said housing for rotating the kelly rod driving sleevein said bearing.

3. In a rotary drilling rig, a power augmenting unit including a pairofcylinders, pistons in the cylinders, a rod connected with each piston, across head connecting the rods, means spacingly connecting the cylindersand forming an enclosed housing having registering openings inthe upperand lower sides thereof, bearings supported in axialalignment with saidopenings, a kelly rod driving sleeve rotatably supported in saidbearings and having a bore to directly engage a kelly rod that isextended therethrough, a chuck sleeve separate from said driving sleeve,thrust bearings rotatably supporting the chuck sleeve in the cross'head,a chuck carried by said last named sleeve having Jaws arranged togrippingly engage the kelly rod, and means in said housing for rotatingthe kelly rod driving sleeve in its supporting bearings.

,4. In a drilling apparatus, power-augmenting means, a cross headactuated by said power augmenting means having an axial bore, a sleevein said bore for passing a kelly rod therethrough, reversely arrangedthrust bearings including outer races at the respective ends of the boreand j inner races on said sleeve, closure plates covering the ends ofsaid bore to retain the outer races, stop means on saidsleeve engagingone of inner races on said sleeve, closure plates covering the ends ofsaid bore to retain theouter races, a stop means on said sleeve engagingone of the inner races, spacing means on the sleeve spacing said innerraces, and a chuck threaded on the end of the sleeve opposite said stopmeans to draw said inner races in rigid assembly withsaid sleeve.

6. In a rotary drilling rig, a power augmenting unit including a pair ofcylinders, a piston in each cylinder, a. rod connected with each piston,a

cross head connecting the rods, means spacingly.

connecting the cylinders and formingan enclosing housing, a kelly roddriving sleeve having a bore'directly engaging a kelly rod, meansrotatably mounting the kelly rod driving sleeve in the housing, a chucksleeve separate from the driving sleeve and rotatably mounted in thecross head, and a chuck fixed to the chuck sleeve for gripping the kellyrod to move the kelly rod through said driving sleeve.

, WALTER T. CALDWELL.

JOHN P. LANG.

